Electrical check equipment



Oct. 19, 1937. c. F. "OESTERMEYER 4 2,095,131

ELECTRICAL CHECK EQUIPMENT Filed Oct. 24. 1935 3 Sheets-Sheet 1 INVENTOR. BY CARL f. 06675544675? ATTORNEYE 3 Sheets$heet 2 INVENTOR.

ATTORNEYS.

Oct. 19, 1937; c. F. OESTERMEYER ELECTRICAL CHECK EQUIPMENT Filed Oct. 24, 1935 u 40 (FE-ou 9 BY C404 FOEJTERMEYER m m m Oct. 19, 1937. c. F. OESTERMEYER ELECTRICAL CHECK EQUIPMENT Filed Oct. 24. 1935- 3 Sheets-$heet 3 INVENTOR. Ow; f. O'STERMEYE/P mpsmo w ATTORNEY).

Patented on. 19, 193v- 2,096,131

UNITED STATES PATENT OFFICE 2,096,131 ELECTRICAL CHECK EQUIPLIENT Carl F. Oestermeyer, Shaker Heights, Ohio, as-

signor to Willard Storage Battery Company, x(lile'lveland, Ohio, a corporation of WcotVir- Application October 24, 1935, Serial No. 46,548 6 Claims. (Cl. 175-483) This invention relates to improvements in elecvolts, this scale being divided up into headings trical check equipment, that is to say, testers for "Inoperative", Low, Fair, and Good'., which various circuits and pieces of apparatus in the are placed there particularly for the information electrical system of a motor vehicle. of owners whose batteries are being tested. Above One of the objects of the invention is the prothe scale ii there is another scale It running up vision of an electrical check equipment which to 1.2 volts, the divisions of which correspond shall be complete and yet simple and relatively with those on a portion of the lower scale it. inexpensive, The scale H is used for measuring the voltage Another object is the provision of an equiploss between the battery and the starting motor 10 ment of this character which shall be capable on either side of the battery when the starting 10 of quick attachment to the battery and other motor is in operation. These two scales cover parts of an automobile electrical system, and the lower range of the voltmeter. For the upper comprising a simple manual control for putting range of the voltmeter there is a scale I! running the apparatus into condition for taking the defrom zero to 10 volts. This scale is marked on sired readings one after another. the face of the meter 10 Volt scale. 16 Another object is the provision of means for The ammeter i2 has a lower scale l6 running taking the voltages of the different cells of a from zero to300 amperes in either direction, this multi-cell battery from a single voltmeter and scale being marked on the meter face Starter without changing the conductor connections from test 300 ampere scale., This scale and this 20 the battery to the test equipment. range of the meter are used only for the meas- 20 A further object is the provision of a double urement of the starter draw, that is the current range voltmeter arranged for selective operation used in operating the starting motor. on the same under the said manual control, so that relatively meter face there is-a second scale I1 running from fine readings may be obtained for the low voltzero to 30 amperes in either direction and labeled age'range. Ampere scale, generator test. At the top 25 Still another object is the provision of equipof the panel there is a push-button l8 which serves ment by means of which the functioning of the when pressed to remove from the ammeter circuit output regulation of an automobile generator may sumcient resistance to give the readings on the be checked, that is to say, when the automobile low range scale l1. By the use of a push-button 30 equipment includes provision for maintaining the switch for this purpose, I guard against the acci- 30 voltage of the generator substantially constant. dental use of the ammeter without this resist- Other objects and features of novelty will apance when a heavy starting current is flowing. pear as I proceed with the description of that The details of this arrangement will appear in embodiment of the invention which, for the the description of the wiring diagrams to follow. purposes of the present application, I have illus- On the lower part of the panel l0 there is a 35 trated in the accompanying drawings, in which tester control knob l9 having a pointer 20. Fig. l is a face view of an instrument board This control knob has six operating positions which may be used in connection with the in- 2i to 26 inclusive. When the pointer 20 is turned ventlon; to one of the three positions 2|, 22, and 23, the 40 Fig.2 is a wiring diagram showing the equipvoltmeter i l is in communication with one of 40 ment set up for checking the cell voltages of a the three cells of the battery being tested, as battery, for checking the load imposed upon the indicated by the markings on Fig. 1. When the battery by the starting motor, and for checking pointer is turned to one of the positions 24 and the voltage loss in the motor conductors; and 25, connections are made for measurement of 5 Fig. 3 is a wiring diagram showing the equipthe voltage loss between the battery and the ment set up for checking the charging rate of a starting motor on either side of the battery, as generator and the automatic regulation thereof. indicated by the inscriptions on, Fig. 1. When In Fig. 1 of the drawings I have shown an the pointer is turned to position 26, certain coninstrument panel III which preferably forms a nections are made to shift from the low range cover for a box, not shown, in which the greater of the voltmeter to the 10 volt range, as will 50 part of the apparatus is contained. A two-range appear presently. voltmeter ii and a two-rangeammeter l2 are 21, 28, and 29 are polarized receptacles adapted mounted on the panel ill. on the face of the to receive polarized plugs on the ends of cord sets, voltmeter there is inscribed a scale ll entitled by means of which connection may be made with Battery cell test with a high reading 0. 2% pieces of apparatus inside or outside of the testing 5 insulation plates upon stat control knob by means of which a variable resistance may be introduced into the ammeter circuit. 3| and 32 are terminal posts which are adapted to receive special connecters on one of the cord sets, these posts having internal connections with the two sides of the rheostat receptacle 23.

Referring now to Figs. 2 and 3, 33 indicates a shaft which projects through the panel 10 and is adapted to be rotated by the knob l9, being pinned or otherwise secured thereto. This shaft has keyed thereto at spaced points along its length a pair of similar switch arms 34 and 35, these arms being insulated from each other. 36 and 31 are which are mounted at evenly spaced intervals contact buttons 4| to 46 inclusive and 5I to 56 inclusive, respectively. In the box beneath the panel I0 there is an insulation board 51 upon which are carried binding posts BI, 62, 63, 65, 66, 61, 68, 13, 14, and 15.

Button 4| is connected with binding post 6I by conductors 16 and 11. Buttons 42 and 43 are connected with binding posts 62 and 63 by conductors 18 and 19 respectively. Button 44 is connected with binding post H by conductor 11. Buttons 45 and 46 are connected with binding posts 155 and 66 by conductors and BI. Buttons 5| and 52 are connected with buttons 42 and 43 by conductors 82 and 83 respectively. Buttons 53, 54, and 55 are connected with binding posts 13, 14, and 15 respectively by conductors 84, 85, and 86.

The switch arms 34 and 35- are connected with binding posts 61 and 68 by conductors 81 and 88 respectively. Binding post 61 is also connected by a conductor 89 to one terminal 90 of the voltmeter II. The binding post 63 is connected by a conductor 9I with another terminal 92 of the voltmeter. When connections are made to the voltmeter between terminals 90 and 92, the readings are on the 2.5 volt scales I3 and I4. A third terminal 93 of the voltmeter is connected by a conductor 94 with one side of the receptacle 28. A conductor 35 leads from the other side of that receptacle to the binding post 66. From one side of the receptacle 21 a conductor 96 leads to binding post 14, while the other side of the receptacle is connected by a conductor 91 with the binding post 66.

0n the ammeter I2 there is a terminal 98 which is connected by a conductor 99 with a contact I00 in an ammeter shunt box. Another terminal I 0| of the ammeter is normally connected through a resistance I02 and a conductor I03 with a contact I04 of the shunt box. When the resistance I02 is in the meter circuit, as it is normally, the meter registers on the 300 ampere scale I6. This resistance may be shunted out, however, through conductors I05 and I06 when push-button I8 is depressed, and then the meter registers on the 30 ampere scale I1.

Within the box which houses the equipment the contact post 3I is connected by a conductor I01 with one side of the polarized receptacle 29. The other side of that receptacle is connected through a conductor I08 and variable resistance I09 with contact post 32. Resistance I09 is adjusted by means of rheostat knob 30.

I will now describe those" connections which are external portions of the equipment, that is, those which extend outside of the box upon which the panel I0 is mounted, it being understood that this box is preferably mounted upon a wheeled carriage which supports the box at a convenient elevation and enables it to be moved readily so that equipment, as will presently appear. 30 is a rheoit may be placed adjacent an automobile on either side thereof or moved from one side to the other, as may be required.

The outside flexible conductors are indicated in the wiring diagrams by heavy lines. As shown in Fig. 2, a conductor I I0 attached to binding post 6 I is detachably connected to the positive terminal post I I I of a three-cell storage battery I I2 such as is ordinarily employed in an automobile. Another conductor I I3 attached to binding post 62 is provided with means for detachable connection with an inter-cell connector II4 joining the positive cell of the battery to the intermediate cell. Another inter-cell connector I I4, joining the intermediate cell and the negative cell, is connected detachably by a. flexible cord II5 with the binding post 63, while the negative terminal II6 of the battery is adapted to be joined with binding post 13 by a flexible conductor I H.

A flexible conductor I I8 leading from a terminal H9 in the ammeter shunt box is adapted to be clamped upon negative terminal II6 of the battery, and another flexible conductor I20 leads from another terminal I2I in the shunt box and is adapted to be clamped onto the extremity of the starting motor cable I22 when the latter has been removed from the negative post I I6 of the battery. I23 represents the starting switch, and I24 indicates the starting motor which may be grounded through a cable I25. The positive terminal of the battery is also grounded through a cable I26. From the extremity of conductor I20 there extends another conductor I21 which runs back to binding post 15.

A polarized plug I28 adapted to be received in receptacle 21 carries projecting contacts that are joined electrically with conductors I29 and I30 respectively. These conductors may be detachably connected with the opposite terminals of the starting motor I24, as indicated in Fig. 2.

' At certain times the conductors H8 and I20 are connected with posts 3| and 32, respectively, as indicated in Fig. 3. At such times, polarized plug I3I-is mounted in receptacle 29. The regular battery cable I32 is disconnected from the generator and its free end connected with one of the conductors I32 of the cord set attached to plug I3I. The other conductor I33 from plug I3I is connected with the terminal I34 of the automobile generator I35 to be tested. At the same time, conductors I36 and I31, which are attached to apolarized plug I38 which is inserted in the receptacle 28, are connected to the terminal'I34 and to the ground on the other side of the generator respectively. It will be understood that the free ends of the various flexible cords above referred to are provided with suitable means, such as spring grip connecters, for conveniently and quickly making the connections with the electrical apparatus of the vehicle. When the connections shown in Fig. 2 have been made, the operator is in readiness to make various tests by the simple expedient of turning the control knob I9 and taking readings from the voltmeter II and the ammeter I2.

Checking battery cell voZtage.-It will be apparent that the positive cell of battery H2 is connected between conductors H0 and H3. The operator turns knob I9 until pointer 20 stands over position 2| on the panel I0, when arms 34 and 35, which are mechanically united and electrically insulated from each other, will engage contact buttons M and 5| respectively. Current will then flow from positive terminal post III of the batterythrough the positive cell thereof to ing post 88, conductor 8|,

thence through conductor II8 to binding post 82, through conductor 18 to contact button 42, thence through conductor 82 to contact button 8I, through switch arm 88 and conductor 88 to binding post 88, thence through conductor 8I to voltmeter terminal 82, through the voltmeter to terminal 88, and back through conductor 88, binding post 81, conductor 81, switch arm 84, contact button 4I. conductors 18 and 11 to binding post 8i, and thence through conductor II8 to battery terminal post III. The reading on the voltmeter is then taken, after which th knob H8 is turned to'bring pointer 28 to the position 22, 'when the arms 84 and 88 will come to rest on contact buttons 42 and 82 respectively. The current now flows through the intermediate cell from connecter II4'to connecter I I4 and from the latter connecter through conductor II8 to binding post 88, conductor 18, contact button 48, conductor 88, contact button 82, switch arm 88, conductor 88, bindterminal 82 of the voltmeter. through the voltmeter to terminal 88,

the connecter II4,

- returning through conductor .88, binding post may then be read on the voltmeter.

81, conductor 81, switch arm 84, contact button 42, conductor 18, bindingpost 82, and conductor II8 back to the battery. The voltage of the intermediate cell is thus registered on the voltmeter.

Next the operator turns knob I8. to position 28, bringing the mechanically united arms 84 and 88 into engagement with contact buttons 48 and 88 respectively. Current then flows through the negative cell of the battery from connecter 4' to terminal post H8, and from that post through conductor II1 to binding post 18, through condutor 84 to contact button 88, through switch arm 88 and conductor 88 to binding post 88, to the voltmeter by way 01' conductor 8|, and back through conductor 88 to Binding post 81 and by way of conductor 81 and switch arm 84 to contact button 48, through conductor 18 to binding post 88, and by way of conductor II 8 back to the battery. The voltage of the negative cell These three readings are of course obtained very quickly and without any change whatever in the electrical connections other than those eilected by the turning of knob I8. These cell voltages are taken preferably under full load, that is, while the starting motor is running and the engine ignition turned on.

Voltage loss in battery to starter connections.- Next the operator turns knob I8 to the fourth position marked 24 on Fig. 1. This brings arms 84 and 88 into engagement with contact buttons 44 and 84 respectively. With the starter switch I28 closed, current flows from the starting motor through cable I28 to ground, thence from ground through cable I28 to positive post III of the battery, through conductor II8 to binding post 8i, thence through conductor 11 to contact button 44, switch arm 84, conductor 81, binding post 81, conductor 88 to voltmeter II, and back through conductor 8| to binding post 88, conductor 88 to switch arm 88, through contact button 84 and conductor 88 to binding post 14, through conductor 88 to receptacle. 21, and through plug I28 and conductor I88 back to cable I28. This measures the voltage drop of the connections on the positive side of the battery extending to the starting motor. I

Having made a, note of this voltage drop, the operator next turns knob I8 to the fifth position, marked 28 on the drawings, where the conductor 81, binding read on the 30 switch arms contact with the buttons 48 and 88. A circuit is then completed from the cable I22 through conductor I28, plug .I28, receptacle 21,

post 88, conductor 88, contact button 48, switch arm 84, conductor 81, binding post 81 and conductor 88 to the voltmeter, and back through conductor 8|, binding post 88, conductor 88, switch arm 88, contact button 88, conductor 88, binding post 18, and conductor I21 to the cable I22." In other words, the voltmeter is bridged across the ends of cable I22 while it forms a part oi the starting motor cir cult. The voltage loss reading for this part of the circuit is now taken from the voltmeter. The allowable voltage losses for these connections may be learned from prepared tables listing various makes and models of automotive vehicles. Obviously, if the readings are too high, the condition of the conductors should be checked and by repair or replacement of defectiveever it is desired to check lamps and various other electrical equipment of an automobile, the ammeter is connected across the terminals oi. the

battery, as by connecting conductor I I8 to battery post II8, as shown in Fig. 2, and connecting the outer extremity oi! conductor I28 to the ground. The operator may then turn on all of the normal driving lamps and check this normal lamp load on the 30 ampere scale I1 by depressing the pushbutton I8. He may then turn on all lamps and all electrical accessories, except such as draw a heavy current momentarily, and check this total load by a reading of the 30 ampere scale. Also the various lamps and accessories may be checked individually for current consumption by turning them on one at a time and depressing the pushbutton I8.

Testing generator and generator regulator.- When it is desired to test the generator and make a check of any automatic output control which may be provided, the control knob I8 is turned to the position marked 28 on the panel and the flexible cord connections illustrated in Fig. 3 are used. Current is then free to pass from generator I88 through ground to positive terminal III of the battery, through the battery and out through terminal H8, conductors I82 and I82, plug I8I, receptacle 28, conductor I81, contact post 8|, conductor II8, terminals H8 and HI, conductor I28, contact post 82, conductor I08, variable resistance I88, receptacle 28, plug I8I, and conductor I88 back to the generator. With the engine running, and with no lamp or accessory load, themaximum charging rate may then be ampere scale by depressing the push-button I8. To obtain this reading, the ensine speed should be increased slowly until the ammeter needle reaches the maximum value. The maximum charging rate under full load is then taken in a similar manner after turning on the lamps and other accessories.

With respect to the voltmeter, a shunt circuit may be traced from the generator through conductor I 88, plug I88, receptacle 28, conductor 88, binding post 88, conductor 8|, contact button 48, switch arm 84, conductor 81, binding post 81, and conductor 88 to terminal 88 of the voltmeter, through the voltmeter to terminal 88 and back through conductor 84, receptacle 28, plug I88, and conductor I81 to the opposite side of the generator. The voltage is read, of course, on the 10 volt scale I8.

Now, assuming that there is. an automatic regulator, in the electrical system of the automobile being checked, such regulator tending to maintain a. predetermined potential across the brushes 0! the generator, and assuming that it is desired to check the operation of such regulator, and further assuming that the connections have been made as in Fig. 3, the operator starts the engine and takes readings of the voltmeter on the 10 volt scale i5, and of the ammeter with the push-button i8 depressed. Any variation in voltage may be noted as the engine speed is increased so as to check the operation of the regulator. The functioning of the regulator is affected by the condition of the battery, that is to say, due to the condition of the battery it may not be possible to obtain a voltage as high as the voltage specified for correct operation of the regulator relay. In order to meet this situa- I tion, I providethe variable resistance I09 which enables the operator to introduce resistance into the generator circuit, thereby increasing the voltage sufiiciently to permit the desired test to be made.

Having thus described my invention, I claim:

1. In a system of the class described, a battery and a starting motor, means for measuring the voltage loss in the line between the battery and the motor on the positive side and the negative side separately, and means under a single manual control for connecting either side of said line to said voltage measuring means selectively.

2. In testing equipment of the character described, a voltmeter, detachable connections adapted to connect the various cells of a battery one at a time with the voltmeter, a detachable connection adapted to be connected with the starting motor of a vehicle, a detachable connection adapted to be connected with the generator of the vehicle, and a common control means for bringing into operative relation selectively any one of the sets of connections for said battery cells, or the connections for the starting motor, or the connections for the generator.

3. In testing equipment of the character de= scribed, an ammeter, a circuit therefor, a variable resistance in said circuit, and means for connecting a generator and a battery into the circult, whereby the voltage of the generator may high ranges, detachable connections adapted to connect the arious cells of the battery one at a time with the low range of the voltmeter, means for connecting the opposite sides of the generator with the high range of the voltmeter, and means, actuated by a single control for selectively cennecting with the'voltmeter said high range connections or any one of said low range connections.

5. In apparatus for testing the electrical equip- 'ment of a motor vehicle including a storage battery and a starter motor, a voltmeter, detachable connections adapted to connect the various cells of the battery one at a time with said voltmeter, detachable connections from the voltmeter adapted for attachment to spaced points on the positive and the negative sides of the line between the battery and the starter, and means ac tuated by a single manual control for selecting and rendering operative any one of said individual cell connections or either one of said connections to the starter line.

6. In apparatus for testing the electrical equip-.

ment of a motor vehicle including a storage battery, a starter motor and a generator, a voltmeter having low and high ranges, detachable conncctions from the low range of the voltmeter adapted for attachment to spaced points on the positive and the negative sides of the line between the battery and the starter, means for connecting the opposite sides of the generator with the high range of the voltmeter, and means actuated by a single manual control for selecting and rendering operative either one of said low range connections to the starter line or said high range connection to the generator.

. CARL F. OESTERMIEYER. 

